New property autoUpdateDate added

• New feature added: autoUpdateDate proposed by #20 to enable auto date update when datepicker is a standalone element on the document (not inside an overlay/ dialog and has no button for date confirmation).
• Merged multiple animations into one single file - to reduce network request when loading this element.
• Updated all dependencies to the latest.
• Fixed #23 for missing dependencies iron-iconset-svg.
• Fixed #24 to increase readability for hovered year in the list view.
• Updated demo to include the newly added property autoUpdateDate.